Automatic sharpening device

ABSTRACT

There is provided an automatic sharpening device comprising a movable block, a device pivotably mounted on said movable block for securing an edged tool, a cylindrical grinding member angularly disposed with respect to the moving direction of the movable block, a device for pivotally inclining said device to press down one edge portion of the edged tool upon the cylindrical grinding member, and a driving device for rotating the grinding member and reciprocating the movable block.

United States Patent [191 Ohashi [4 1 May 20, 1975 AUTOMATIC SHARPENING DEVICE [76] Inventor: Taro Ohashi, 2809 Kobubo, Futtsu-shi, Chiba-ken, Japan [22] Filed: Oct. 3, 1973 [21] Appl. No.: 403,254

[30] Foreign Application Priority Data July 4, 1973 Japan 48-79548 [52] US. Cl. 51/91 BS; 51/92 BS; 51/159; 51/224; 51/285 [51] Int. Cl. B24b 7/02 [58] Field of Search 51/74 BS, 74 R, 91 BS, 51/91 R, 92 BS, 92 R, 159, 206 R, 218 R, 1 224, 285

[56] References Cited UNITED STATES PATENTS 207,717 9/1878 Creager 51/206 R 1,087,527 2/1914 Button........ 1,126,891 2/1915 Sheppard.... 2,637,150 5/1953 McQuary 1. 51/92 R 2,663,976 12/1953 Jacoby 51/92 R 2,697,900 12/1954 Lewis 51/289 R 3,016,658 l/l962 Pondexter.... 51/159 3,574,268 4/1971 Buse 51/92 BS 3,618,268 11/1971 Sunnen 51/92 R 3,768,211 10/1973 Costa 51/227 H Primary ExaminerA1 Lawrence Smith Assistant Examiner-Robert C. Watson. Attorney, Agent, or Firm-Eliot S. Gerber [57] ABSTRACT There is provided an automatic sharpening device comprising a movable block, a device pivotably mounted on said movable block for securing an edged tool, a cylindrical grinding member angularly disposed with respect to the moving direction of the movable block, a device for pivotally inclining said device to press down one edge portion of the edged tool upon the cylindrical grinding member, and a driving device for rotating the grinding member and reciprocating the movable block.

6 Claims, 7 Drawing Figures PATENTEDHAYZOI975 $883,995

SHEH 2 BF 4 PATEN-FED W 2 0 I975 SHEET H31 4 AUTOMATIC SHARPENING DEVICE The present invention relates to an automatic sharpening device for sharpening edged tools including cutlery, and more particularly to an automatic sharpening device for a tool having an elongated blade such as a razor blade used at a barbers.

As is known, a blade of the razor used by a barber is not straight but slightly curved with respect to a base portion thereof and it is very difficult to sharpen the curved razor blade by sliding it on a surface of a grindstone. That is, a special and skilled technique has been needed to sharpen edged tools as razors. Moreover, grindstones do not always have flat surfaces, and this makes it more difficult to sharpen a razor blade.

Accordingly, an object of the present invention is to provide a device for automatically and evenly sharpening a blade of an edged tool such as a razor.

Another object of the present invention is to provide a device for automatically and evenly sharpening both surfaces of an elongated edge of an edged tool such as a razor.

A further object of the present invention is to provide an automatic sharpening device applicable for sharpening many kinds of edged tools.

According to the present invention, there is provided an automatic sharpening device for sharpening an edged tool comprising a movable block reciprocable above a base plate, means pivotably mounted on the movable block for securing the edged tool, a cylindrical grinding member angularly disposed with respect to the moving direction of the movable block, means for pivotablly inclining the securing means to press down one edge side portion of theedged tool on the cylindrical grinding member, and driving means for rotating the cylindrical grinding member and reciprocating the movable block.

The aforementioned and other objects and features of the present invention will become apparent from the detailed description thereof, which is to be read with reference to the accompanying drawings, in which:

FIGS. 1 and 2 are perspective views of embodiments of an automatic sharpening device of the present invention;

FIG. 3 is a perspective view of a driving mechanism for use with the sharpening device of the present invention;

FIGS. 4(a), (b), (c) are partly sectioned side views of a principle mechanism of the sharpening device according to the present invention, showing how both surfaces of the edge of the edged tool are turned over to be sharpened; and

FIG. 5 is a perspective view of an attachment for sharpening a scissor blade.

Referring now to FIG. 1, there are provided on a base 1 two substantially rectangular supporting plates 2a and 2b facing each other in a predetermined spaced relation. The supporting plates 2a and 2b are positioned in an upright manner and have right-angled triangular reversing guides 3a and 3b at upper portions thereof and holes 4a and 4b at lower portions thereof. Between the supporting plates 2a and 2b a movable block 5 is disposed. The movable block 5 formed with a base portion 5a and two side portions 5b and 5c to form a U- shape. The U-shaped movable block 5 has two throughholes at the side portions 5b and 56 thereof, and is suspended by two guide rods 6a and 6b which are slidably inserted into the through-holes of the movable block 5.

The guide rods 6a and 6b are connected at the ends thereof to the supporting plates so that the movable block 5 is suspended by and slidably movable along the guide rods 6a and 6b. The movable block 5 is provided with a first axial rod 7a and a second axial rod 7b, both rods being rotatably connected to inner surfaces of the side portions 5b and 5c of the U-shaped movable block 5. The both axial rods 7a and 7b are disposed parallel to one another, and the first axial rod 7a is located above the second axial rod 7b. The first axial rod 7a is fixedly connected to a securing member 8, a first toothed wheel 9a, and a first arm 10. The securing member 8 and the first toothed wheel 9a are disposed fixedly on the first axial rod 7a between the side portions 5b and 5c of the U-shaped movable block 5, and the first arm 10 is fixedly connected to one end of the first axial rod 7a at an outer surface of the side portion 5c of the movable block 5.

The securing member 8 extends over the side portion 5b at right angles to the moving direction of the movable block 5, and has means 11 for holding and securing a razor l2 and has a hook 13 for preventing a sheath portion 12a of the razor 12 from jumping away during the sharpening operation. The holding means 11 firmly holds the razor 12 on the securing member 8 by an adjustment screw 11a so that an inclination of the securing member 8 about the first axial rod 7a inclines the razor 12. The securing member 8 has a base portion 8a, a tip portion 8b, and an axial portion 8c so that the tip portion 8b, which receives a neck of the razor blade 12 as shown in FIG. 1, slightly moves about the axial portion 8c by providing a small space (not shown) between the tip portion 8b and the base portion 8a.

There is also provided a tension spring 15 connected at its upper end to the first arm 10 through a rod 14, and at its lower end to the side portion 5c of the movable block 5 so that the tension spring 15 travels together with the movable block 5. The tension spring 15 presses down one edge portion of the edged tool such as a razor upon a cylindrical grining member, and a detail of which will be described later.

The second axial rod 7b is fixedly provided with a second toothed wheel 9b and a second arm 17 having a protrusion 18 adjacent its tip portion. The protrusion 18 extends laterally so that it may be parallel to the second axial rod 7b. The second toothed wheel 9b is so constructed that it meshes with the first toothed wheel 9a disposed above it.

On the base 1, there is further provided a table 19 beside the space where the movable block 5 moves along the guide rods 6a and 6b. The table 19 is so constructed that its upper surface is parallel to the surface of the base 1 as shown in FIG. 1. On the table 19, a cylindrical grinding member 20 made of balsa is removably disposed, angularly with respect to the moving direction of the movable block 5. The cylindrical grinding member 20 has an axial rod 21 extending from the sides thereof, the axial rod 21 being removably and rotatably mounted on supporting means 22. The supporting means 22 is disposed on an elongated plate 23 which is pivotably connected to the table 19 by a pin 24 so that the grinding member 20 may be pivoted about the pin 24 to vary the angle between the longitudinal axis of the cylindrical grinding member 20 and the travelling direction of the movable block 5.

In the construction described, the cylindrical grinding member 20 pivots about the pin 24 so that the angle of the cylindrical grinding member with respect to the moving direction may be altered by moving the elongated member 23.

The elongated member 23 has a bolt and a threaded hole (not shown) for the bolt on its one end. When the angle of the cylindrical grinding member 20 with respect to the moving direction of the movable block is determined by a guage plate 26 which is provided on the table 19, the elongated member is fixed on the table 19 by the bolt 25 to fix the angle of the cylindrical grinding member 20.

When a cylindrical grinding member made of steel, rather than balsa, is needed, the cylindrical grinding member 20 made of balsa is removed and replace with the steel grinding member.

As shown in FIG. 2 showing another embodiment of the present invention, there may preferably be disposed a guide bar 44, one end of which is connected to the supporting plate 2a and the other end of which is connected to the other supporting plate 2b. The guide bar 44 is inclined and has a slope with respect to a surface of the base plate 1 such that the guide bar 44 is acclivous toward the supporting plate 2b. In this embodiment, the tension spring 15, the upper end of which is connected directly to the first arm 10, has at its lowest end a block 16 having a through hole through which the guide bar 44 is movably inserted. The tension spring is then 15 movable along the guide bar 44 together with the movable block 5. The tension spring 15 acts so as to press the edged portion of the razor 12 upon the cylindrical grinding member 20 with a greater tension as the movable block 5 travels toward the supporting plate 2a since the guide bar 14 is inclined with respect to the surface of the base 1 in such a manner that it is acclivous toward the supporting plate 2b as described above. By the construction of the acclivous guide bar 14 and the tension spring 15, the edged portion of the razor is evenly pressed upon the cylindrical grinding member 20, thereby grinding and sharpening the razor evenly. The embodiment of the guide bar presents a great advantage particularly when it is desired to sharpen a razor blade, the edge of which is curved.

A driving means is provided between the table 19 and the base 1 for rotating the cylindrical grinding member 20 and reciprocating the movable block 5 along the guide rods 6a and 6b, a detailed mechanism of which.

is described below. In FIG. 3, a rope-pulley'27 is operatively connected to a second rope-pulley 28 by an endless rope 29 passing under two grooved wheels 30a and 30b. The rope-pulley 28 is located adjacent a toothed wheel 31 of the grinding member 20 and fixedly connected to a toothed wheel 32. The toothed wheels 31 and 32 are meshed with each other so that the ropepulley rotates the grinding member 20. The rope-pulley 27 has a disc member 33, which has a diameter smaller '1 than the radius of the rope-pulley 27, between the center and the circumference of the rope-pulley. The disc member 33 has a shaft 34, and a pin 35. The shaft 34 is rotatably connected at its one end to an eccentric portion of the disc member 33 and the other end thereof is rotatably connected to a disc 36. The pin 35 laterally extends from an edge of the disc member 33, and an arc-shaped plate spring 37 having grooves 37a and 37b at both its ends is disposed adjacent to the disc member 33 so that the groove 37a is positioned adjacent to the circumference of the rope-pulley 27 and that the other groove 37b is positioned adjacent to an axis of the rope-pulley. The pin 35 engages either the groove 37a or the groove 37b.

When a razor is sharpened, the pin 35 is secured and positioned at the groove 37a to lengthen the stroke of the shaft 34 so that the movable block 5 fully travels along the guide rods 6a and 6b until the protrusion 18 on the second arm 17 is pushed downward to turnover or reverse the razor.

In the case of sharpening a scissor blade, however, the pin 35 is positioned at the other groove 37b so as to shorten the stroke of the shaft 34. The shorter stroke of the shaft 34 makes the movable block 5 travel for a shorter distance along the guide rods 6a and 6b so that the protrusion 18 of the second arm 17 does not touch the reversing guides 3a and 3b. In this case, the securing member is not reversed, i.e., does not turn over. While razor-sharpening needs a reversing movement of the securing member 8 so that both edged portions or surfaces of the razor may be sharpened, the sharpening of a scissor blade does not receive the reversing movement of the securing member 8 since the scissor blade does not need to be sharpened on its both edged portions or surfaces. This is the reason why the pin 35 is positioned at the groove 37b to shorten the stroke of the shaft 34 when the scissor blade is sharpened.

The disc 36 comprises thereon a deltoid pinion 38 which meshes with an elongated rack 39. The rack 39 is fixedly connected to the movable block 5, whereby a pivotal movement of the disc 36 reciprocates the movable block 5.

The pulley 27 is connected by a rod 40 with a worm wheel 41 which is rotated by a motor 42 through a worm 43. In the construction of the driving mechanism as described above, the motor 42 rotates the cylindrical grinding member 20 and reciprocates the movable block 5.

In operation, the motor 42 rotates the pulley 27 by way of the worm 43 and the worm wheel 41. Then the pulley rotates the grinding member 20 and at the same time pivots the disc 36 through the shaft 34. The pivotal movement of the disc 36 allows the rack 39 to gether with the movable block 5 to move reciprocally by way of the deltoid pinion.

In FIG. 3, though it is shown that the pin 35 is positioned at and engaged with the groove 37b of the arcshaped plate spring 37, the pin 35 may be positioned at and engaged with the other groove 37a by operating a handle 52 in order to change a reciprocating stroke of the shaft 34, thereby changing the reciprocating distance of the movable block 5. This construction is of use particularly for a case in which an edged tool does not have to be reversed for sharpening both surfaces of the edge, as described before. In other words, since only one surface of the edged tool such as a scissor blade is ground to be sharpened, the reciprocating stroke of the shaft 34 should be shorter so that the movable block 5 does not travel further along the guide rods 6a and 6b after the protrusion of the second arm 17 approaches the triangular reversing guides 3a and 3b.

In FIGS. 4(a), (b) and (c), it is shown how an edged tool such as a razor 12, which is secured by the securing member 8, is reversed or turned over while the movable block 5 is reciprocated. In FIG. 4(a), securing member 8 is inclined to the right hand side of the drawing by the tension of the tension spring 15 so that an edge surface of the razor 12 is pressed on the cylindrical grinding member 20. The movable block 5 travels along the guide rods 6a and 6b (shown in FIG. 1) toward the right hand side in the drawing, i.e. toward the supporting member 2b, while the razor 12 is being ground by the cylindrical grinding member 20 rotated by the driving mechanism shown in FIG. 3. When movable block 5 further goes on travelling, the protrusion 18 of the second arm 17 comes to touch the side of the reversing guide 3b, and as the movable block 5 further travels, the protrusion 18 slides beneath the side of the reversing guide 3b. As the protrusion 18 goes on sliding beneath the obliquely-formed side of the reversing guide 3b, the second arm 17 continues to rotate about the second axial rod 7b in the clockwise direction until the protrusion 18 comes to the lowest portion as shown in FIG. 4(b), and the first arm 10 is rotated in the counterclockwise direction against the tension of the tension spring 15. When the second arm 17 is rotated until the protrusion 18 slides into the lowest position as shown in FIG. 4(b), the first arm 10 also rotates into the upright position, and the inclined securing member 8 also turns to stand erect against the tension of the tension spring 15, as shown in FIG. 4(b). Then, a little further advancement of the movable block 5 from the position shown in FIG. 4(b) makes the second arm 17 rotate further, and at this instance, the erected securing member 8 is forced to be inclined toward the left hand side by the tension of the tension spring 15. After the securing member 8 is inclined toward the left hand side, the movable block 5 starts travelling again toward the supporting member 2a as shown in FIG. 4(c). The reciprocating travel of the movable block 5 toward the supporting member 2a and toward the supporting member 2b are repeated so that the movable block 5 reciprocates along the guide rods 6a and 6b. The holes 4a and 4b of the supporting plates 2a and 2b allow the full movement of the rack 39 such that the rack 39 connected to the movable block 5 may not collide with the supporting plates 2a and 211. I

FIG. 5 shows an attachment 46 for sharpening a scissor blade 47. The attachment 46 is mounted on the movable block 5 and comprises means 48 for adjusting the angle of contact of the scissor blade 47 with the cylindrical grinding member 20. In this construction, 'a bar 49 is disposed so that one end is positioned on a spring 500 and the other end is positioned on another spring 50b shown in FIG. 1. The 'tension of the spring 50a is stronger than that of the other spring 50b. Both springs are disposed on the supporting plate 2a and 2b. The attachment 46 also has a member 51 having a wheel 51a so that the member 51 with wheel 51a trav els on the bar 49. Since the bar 49 is supported by the stronger tension spring 50a and the weaker tension spring 50b, the scissor blade, an edge portion of which is usually curved and warped toward a tip thereof, is pressed with stronger pressure as the attachment 46 and the movable block 5 travel toward the supporting member 2a. By the construction described, the whole edged portion of the scissor blade can be sharpened evenly. In other words, the strong tension spring 50a and the weaker tension spring 50b allow the scissor blade to be sharpened evenly since the scissor blade is not straight but slightly curved. In operation, the driving mechanism shown in FIG. 3 rotates the grinding member 20 and reciprocates the movable block 5 along 6 the guide rods 6a and 6b together with an attachment 46 which holds the scissor blade 47.

According to thefpresent invention, the edged tools can'be sharpened automatically and quite easily by an unskilled person. Particularly, the construction of the present invention allows the edged tools to be sharpened uniformly even when the edge' of the tool is curved, since the sharpening operation is achieved in a point-contact manner. Moreover, according to the present invention, not only a razor which is sharpened on both edge surfaces but also a scissor blade or the like which needs sharpening only on one edge surface can be sharpened automatically and evenly by controlling the travelling distance of the movable block. Furthermore, the combination of the acclivous guide bar 44 and the tension spring which are preferably embodied can present a much more uniform sharpening operation.

Though the present invention has been described by way of a preferred embodiment thereof, it will be apparent to those skilled in the art that many modifications and alternations may be made within the scope of the spirit of the present invention. For example, the razor 12 may be secured by the securing member so that the edged portion thereof may face the advancing direction of the travel of the razor together with the movable block 5, though FIGSfl and 2 show that the razor 12 is secured with its edge portion back toward the advancing direction of the travel thereof.

What is claimed is:

1. An automatic sharpening device for sharpening an edged tool, comprising:

a base plate;

a pair of supporting members mounted on said base plate and having a rod extending between said supporting members;

a cylindrical grinding member whose axis is angularly disposed with respect to said rod;

a movable block which is reciprocally mounted on said rod;

a member for holding said edgedtool angularly with respect to the axis of said cylindrical grinding member, said holding member being pivotally mounted on said movable block and having a first inclined position where one side of said edged tool contacts said grinding member and a second inclined position in which the other side of said edged tool contacts said grinding member;

a spring means for biasing said holding member to said first inclined position while said movable block moves in one direction away from one of said supporting members and biasing said holding member to said second inclined position while said movable block moves in the opposite direction away from the other of said supporting members, said spring means being connected at one end to said movable block and operatively connected at the other end to said holding member;

a pair of guide members provided on said supporting members for turning said holding member from one of its inclined positions to its other inclined position against the spring force of said spring means when said movable block comes to said guide member; and

driving means for rotating said grinding member and reciprocating said movable block.

2. An automatic sharpening device as claimed in claim 1 wherein said holding member has a first fixed axial member rotatably supported on said movable block, said first axial member being fixedly provided with a first arm having two end portions, said spring means being connected at one of said end portions thereof, a second axial member rotatably supported on said movable block and having a second gear fixed thereon, a first gear member which is engaged with said second gear, said second axial member being fixedly provided with a second arm cooperable with said guide members, said second arm being swung in one direction and then in the other opposite direction when cooperated with said guide members, thereby turning said holding member to said first and second positions at both ends of said grinding member.

3. An automatic sharpening device as claimed in claim 1 and further comprising a bar member obliquely declined in one direction with respect to said base plate and mounted at both ends thereof on said pair of said supporting members, said bar member gradually becoming higher with respect to said base plate as the distance between said grinding member and said bar member becomes shorter, said spring means being guided at the lower end thereof by said bar member.

4. An automatic sharpening device as claimed in claim 2 wherein said guide means has a pair of triangular members, each of said triangular members having a surface which slants downward, and said second arm has a protrusion which is guided by said slant surfaces to rotate said second axial member, thereby moving said holding member to said first and second inclined members.

5. An automatic sharpening device as claimed in claim 1, wherein said cylindrical grinding member is made of balsa treated to be harder on its circumferential surfaces.

6. An automatic sharpening device as claimed in claim 1, further comprising an attachment for sharpening scissors on said cylindrical grinding member, said attachment being mounted on said movable block and having means for adjusting angles of contact of the scissors with said cylindrical grinding member. 

1. An automatic sharpening device for sharpening an edged tool, comprising: a base plate; a pair of supporting members mounted on said base plate and having a rod extending between said supporting members; a cylindrical grinding member whose axis is angularly disposed with respect to said rod; a movable block which is reciprocally mounted on said rod; a member for holding said edged tool angularly with respect to the axis of said cylindrical grinding member, said holding member being pivotally mounted on said movable block and having a first inclined position where one side of said edged tool contacts said grinding member and a second inclined position in which the other side of said edged tool contacts said grinding member; a spring means for biasing said holding member to said first inclined position while said movable block moves in one direction away from one of said supporting members and biasing said holding member to said second inclined position while said movable block moves in the opposite direction away from the other of said supporting members, said spring means being connected at one end to said movable block and operatively connected at the other end to said holding member; a pair of guide members provided on said supporting members for turning said holding member from one of its inclined positions to its other inclined position against the spring force of said spring means when said movable block comes to said guide member; and driving means for rotating said grinding member and reciprocating said movable block.
 2. An automatic sharpening device as claimed in claim 1 wherein said holding member has a first fixed axial member rotatably supported on said movable block, said first axial member being fixedly provided with a first arm having two end portions, said spring means being connected at one of said end portions thereof, a second axial member rotatably supported on said movable block and having a second gear fixed thereon, a first gear member which is engaged with said second gear, said second axial member being fixedly provided with a second arm cooperable with said guide members, said second arm being swung in one direction and then in the other opposite direction when cooperated with said guide members, thereby turning said holding member to said first and second positions at both ends of said grinding member.
 3. An automatic sharpening device as claimed in claim 1 and further comprising a bar member obliquely declined in one direction with respect to said base plate and mounted at both ends thereof on said pair of said supporting members, said bar member gradually becoming higher with respect to said base plate as the distance between said grinding member and said bar member becomes shorter, said spring means being guided at the lower end thereof by said bar member.
 4. An automatic sharpening device as claimed in claim 2 wherein said guide means has a pair of triangular members, each of said triangular members having a surface which slants downward, and said second arm has a protrusion which is guided by said slant surfaces to rotate said second axial member, thereby moving said holding member to said first and second inclined members.
 5. An automatic sharpening deviCe as claimed in claim 1, wherein said cylindrical grinding member is made of balsa treated to be harder on its circumferential surfaces.
 6. An automatic sharpening device as claimed in claim 1, further comprising an attachment for sharpening scissors on said cylindrical grinding member, said attachment being mounted on said movable block and having means for adjusting angles of contact of the scissors with said cylindrical grinding member. 